When underwriters verify income, how is this accomplished? - aside from just looking at what I sent them.   Let's say I forge all the numbers on my tax returns, w2's, paystubs, etc. etc.. would they be able to catch this or verify that what I submitted is false?  From what I'm reading, they go off of what you submit to them. I know how it sounds, i just can't seem to get an answer online anywhere.  

I have multiple streams of income and every time I have to go through an income verification process they don't even use all of my income - I give them everything and they work with it. But for those that they do select they verify it from the employer side of things. 

What you are describing is illegal.